<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
	<script type="text/javascript">
		var a = 2, b = 3, c = 4, d = 5;
		a = a + b + c + d;
		b = a - b - c - d;
		c = a - b - c - d;
		d = a - b - c - d;
		a = a - b - c - d;
		alert(a);
		alert(b);
		alert(c);
		alert(d);
	</script>
</body>
</html>